cbcvebase.
CVE-2025-21854
published 2025-03-12

CVE-2025-21854: In the Linux kernel, the following vulnerability has been resolved: sockmap, vsock: For connectible sockets allow only connected sockmap expects all vsocks to…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.20%
9.6th percentile
In the Linux kernel, the following vulnerability has been resolved: sockmap, vsock: For connectible sockets allow only connected sockmap expects all vsocks to have a transport assigned, which is expressed in vsock_proto::psock_update_sk_prot(). However, there is an edge case where an unconnected (connectible) socket may lose its previously assigned transport. This is handled with a NULL check in the vsock/BPF recv path. Another design detail is that listening vsocks are not supposed to have any transport assigned at all. Which implies they are not supported by the sockmap. But this is complicated by the fact that a socket, before switching to TCP_LISTEN, may have had some transport assigned during a failed connect() attempt. Hence, we may end up with a listening vsock in a sockmap, which blows up quickly: KASAN: null-ptr-deref in range [0x0000000000000120-0x0000000000000127] CPU: 7 UID: 0 PID: 56 Comm: kworker/7:0 Not tainted 6.14.0-rc1+ Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:vsock_read_skb+0x4b/0x90 Call Trace: sk_psock_verdict_data_ready+0xa4/0x2e0 virtio_transport_recv_pkt+0x1ca8/0x2acc vsock_loopback_work+0x27d/0x3f0 process_one_work+0x846/0x1420 worker_thread+0x5b3/0xf80 kthread+0x35a/0x700 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x1a/0x30 For connectible sockets, instead of relying solely on the state of vsk->transport, tell sockmap to only allow those representing established connections. This aligns with the behaviour for AF_INET and AF_UNIX.

Affected

15 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.17-1 (forky)linux 6.12.17-1 (forky)
linuxlinux
linuxlinux>= 634f1a7110b439c65fd8a809171c1d2d28bcea6f < cc9a7832ede53ade1ba9991f0e27314caa4029d8cc9a7832ede53ade1ba9991f0e27314caa4029d8
linuxlinux>= 634f1a7110b439c65fd8a809171c1d2d28bcea6f < 22b683217ad2112791a708693cb236507abd637a22b683217ad2112791a708693cb236507abd637a
linuxlinux>= 634f1a7110b439c65fd8a809171c1d2d28bcea6f < f7b473e35986835cc2813fef7b9d40336a09247ef7b473e35986835cc2813fef7b9d40336a09247e
linuxlinux>= 634f1a7110b439c65fd8a809171c1d2d28bcea6f < 8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f8fb5bb169d17cdd12c2dcc2e96830ed487d77a0f
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.17-16.12.17-1
linuxlinux_kernel>= 0 < 6.12.17-16.12.17-1
linuxlinux_kernel>= 0 < 6.8.0-78.786.8.0-78.78
linuxlinux_kernel>= 6.13 < 6.13.56.13.5
linuxlinux_kernel>= 6.4 < 6.6.806.6.80
linuxlinux_kernel>= 6.7 < 6.12.176.12.17
msrcazl3_kernel_6.6.78.1-3_on_azure_linux_3.0
msrcazl3_kernel_6.6.82.1-1_on_azure_linux_3.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
vendor_ubuntu5.5MEDIUM
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